US9213270B2 - Image forming apparatus - Google Patents

Image forming apparatus Download PDF

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Publication number
US9213270B2
US9213270B2 US13/597,025 US201213597025A US9213270B2 US 9213270 B2 US9213270 B2 US 9213270B2 US 201213597025 A US201213597025 A US 201213597025A US 9213270 B2 US9213270 B2 US 9213270B2
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United States
Prior art keywords
guide member
housing
image forming
forming apparatus
guide
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US13/597,025
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US20130051854A1 (en
Inventor
Tetsushi Sakuma
Takeshi Sakashita
Masanari Fujita
Mitsutoshi Kichise
Yuuji Meguro
Masato Tsuji
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Ricoh Co Ltd
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Ricoh Co Ltd
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Priority claimed from JP2011186389A external-priority patent/JP5849533B2/ja
Priority claimed from JP2011186385A external-priority patent/JP5800220B2/ja
Application filed by Ricoh Co Ltd filed Critical Ricoh Co Ltd
Assigned to RICOH COMPANY, LTD. reassignment RICOH COMPANY, LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: FUJITA, MASANARI, KICHISE, MITSUTOSHI, MEGURO, YUUJI, TSUJI, MASATO, SAKASHITA, TAKESHI, SAKUMA, TETSUSHI
Publication of US20130051854A1 publication Critical patent/US20130051854A1/en
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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/14—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base
    • G03G15/16—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base of a toner pattern, e.g. a powder pattern, e.g. magnetic transfer
    • G03G15/1605—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base of a toner pattern, e.g. a powder pattern, e.g. magnetic transfer using at least one intermediate support
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/14—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base
    • G03G15/16—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base of a toner pattern, e.g. a powder pattern, e.g. magnetic transfer
    • G03G15/1695—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base of a toner pattern, e.g. a powder pattern, e.g. magnetic transfer with means for preconditioning the paper base before the transfer

Definitions

  • the present invention relates to an image forming apparatus.
  • an image forming apparatus using an electrophotographic method employs charged toner having a polarity to form a toner image on a surface of a photoreceptor, and transfers the toner image to an intermediate transfer belt as a primary transfer. Subsequently, the toner image on the intermediate transfer belt is secondarily transferred to a recording medium, where a fixing process fixes the image on the medium to form a final image.
  • the intermediate transfer belt and a transfer roller form a secondary transfer nip in between.
  • a transfer electrical field is formed at the secondary transfer nip that transfers the toner image on the intermediate transfer belt en bloc to the recording medium.
  • a space M i.e., an electrical discharge area
  • part of toner on the intermediate transfer belt 100 disperses due to discharging generated by the electrical field and the dispersed part of toner attaches to the recording sheet P, thereby causing the image on the recording sheet P to be disturbed.
  • a roller 300 is additionally disposed before the secondary transfer nip N to cause the intermediate transfer belt 100 and the recording sheet P to be closely attached to each other before the space M, thereby minimizing the effect of the electrical discharge.
  • disposition of the roller 300 to change a route of the intermediate transfer belt 100 may cause a cost rise, and increase in the thickness of the transfer device due to the enlarged mounting space, which may cause the transfer device to be larger.
  • JP-2006-301509-A, JP-2008-026533-A, and JP-4038328-B disclose an image forming apparatus using this type of guide before the transfer nip.
  • JP-4038328-B discloses provision of two guide members so as to keep a close contact between the image carrier and the transfer member, which increases the size of the apparatus.
  • the present invention provides an improved image forming apparatus including a guide member having a higher positional precision with respect to the transfer member.
  • the image forming apparatus is compact, easy to maintain, and forms high-quality images.
  • the present invention includes a transfer device rotatably driven while carrying a toner image thereon; a rotary transfer member to form a transfer nip for transferring the toner image on the transfer device to a recording medium; a housing rotatable about a first rotation center together with the rotary transfer member and capable of switching between a closed state to form the transfer nip and an open state eliminating the transfer nip by the rotating about the first rotation center; a guide member to guide the recording medium conveyed through a conveyance path toward upstream in the direction of rotation of the transfer device than the transfer nip, the guide member being supported by the housing; a support frame to support the transfer device; a biasing member to bias the guide member; and a receiving part, disposed on the support frame, configured to contact the guide member biased by the biasing member and position the guide member in the closed state of the housing.
  • the image forming apparatus further includes a rotary sliding unit allowing a rotary movement about a second rotation center and a reciprocal slid
  • FIG. 1 is a cross-sectional view of an image forming apparatus according to an embodiment of the present invention
  • FIGS. 2A and 2B each show a general structure of a guide member with a housing and a transfer device according to an embodiment of the present invention
  • FIG. 3A shows an oblique view of the guide member
  • FIG. 3B is an enlarged side view of a part where the guide member and a receiving member contact
  • FIG. 3C is an enlarged view of a rotary sliding unit
  • FIGS. 4A and 4B each are a side view illustrating the guide member in the housing moving from a closed state to an open state;
  • FIGS. 5A and 5B each are a side view illustrating the guide member in the housing open state
  • FIGS. 6A and 6B each are a side view illustrating the guide member in the housing moving from an open state to a closed state;
  • FIGS. 7A and 7B each are a side view illustrating the guide member in the housing closed state
  • FIG. 8 is a graph showing a relation between image disturbance evaluation and distance between a contact start position of a recording medium with respect to a transfer belt and a secondary transfer nip;
  • FIGS. 9A and 9B each are a side view illustrating the guide member in the housing when a thick sheet is conveyed
  • FIGS. 10A and 10B each are a side view illustrating the guide member having further another exemplary structure
  • FIG. 11 is a side view illustrating the guide member having still further another exemplary structure
  • FIGS. 12A and 12B each are a side view illustrating the guide member having further another exemplary structure
  • FIG. 13A is a side view illustrating the guide member having another structure and FIG. 13B is an enlarged view of a part in FIG. 13A ;
  • FIG. 14 is a side view illustrating a general structure of the guide member in a housing and a transfer device according to another embodiment of the present invention.
  • FIG. 15 is a side view illustrating the guide member in the housing open state
  • FIGS. 16A and 16B are side views illustrating another configuration of the guide member and a regulation member and FIG. 16C is an oblique view illustrating a part of FIGS. 16 A and 16 B;
  • FIG. 17 is an oblique view of the guide member and the regulation member illustrating another exemplary structure
  • FIG. 18 is a side view illustrating a receiving part in another exemplary structure
  • FIG. 19 is a side view of a conventional transfer device illustrating a general configuration thereof.
  • FIG. 20 is a side view of a conventional transfer device illustrating a general configuration thereof.
  • FIG. 1 shows an image forming apparatus according to an embodiment of the present invention.
  • the image forming apparatus 1 includes an exposure unit (not shown), an image forming unit 2 , a transfer device 3 , a sheet feed unit 4 , a conveyance path 5 , a fixing unit 5 , and the like.
  • the exposure unit is disposed in an upper part of the image forming apparatus 1 and includes a power source to emit laser beams and various optical systems. Specifically, the exposure unit directs laser beams L for each color-decomposed component of an image which will be formed based on image data obtained from an image reading means, not shown, onto a photoreceptor drum 22 of the image forming unit 2 , so that a surface of the photoreceptor drum 22 is exposed according to the image data.
  • the image forming unit 2 is disposed below the exposure unit and includes a plurality of process units 21 , which are detachably attached to the image forming apparatus 1 .
  • Each process unit 21 includes the photoreceptor drum 22 capable of carrying toner as a developer on a surface thereof; a charging roller 23 to uniformly charge a surface of the photoreceptor drum 22 ; a developing device 24 to supply toner on the surface of the photoreceptor drum 22 ; and a cleaning blade 25 to clean the surface of the photoreceptor drum 22 , and the like.
  • the developing device 24 contains the toner initially having a negatively charged polarity.
  • Each process unit 21 has a same structure except that each includes a different color of toner such as yellow (y), magenta (m), cyan (c), and black (Bk), and therefore, reference numerals are omitted.
  • the transfer device 3 is disposed directly below the image forming unit 2 .
  • the transfer device 3 includes a drive roller 31 and a driven roller 32 both serving as a support member; a rotary intermediate transfer belt 33 , a transfer member, rotatably stretched around the drive roller 31 and the driven roller 32 ; a belt cleaning unit 34 to clean a surface of the intermediate transfer belt 33 ; a primary transfer roller 35 formed of a metal material, disposed at a position opposed to the photoreceptor drum 22 of each process unit 21 with the intermediate transfer belt 33 sandwiched between; and the like.
  • Each primary transfer roller 35 presses against an interior surface of the intermediate transfer belt 33 at each disposed position and a primary transfer nip is formed at a position where the pressed portion of the intermediate transfer belt 22 contacts each photoreceptor drum 22 .
  • a primary transfer nip is formed at a position where the pressed portion of the intermediate transfer belt 22 contacts each photoreceptor drum 22 .
  • the driven roller 32 is biased, by a compression spring (not shown), against the intermediate transfer belt 33 in such a direction to give a tension to the intermediate transfer belt 33 .
  • the drive roller 31 may be formed of polyurethane rubber (with a thickness of 0.3 to 1 mm) or a thin-layer coating roller (with a thickness of 0.03 to 0.1 mm).
  • the driven roller 32 is formed of aluminum with a press-fitted flange, not shown, to regulate wobbling of the intermediate transfer belt 33 .
  • the intermediate transfer belt 33 is an endless belt formed of a resin film in which a conductive material is dispersed.
  • resin films include vinylidene fluoride (PVDF), ethylene-4-ethylene fluoride copolymers (ETFE), polyimide (PI), polycarbonate (PC), thermally plastic elastomer (TPE), and the like.
  • PVDF vinylidene fluoride
  • ETFE ethylene-4-ethylene fluoride copolymers
  • PI polyimide
  • PC polycarbonate
  • TPE thermally plastic elastomer
  • a belt with a coefficient of elasticity of 1000 to 2000 Mpa, a thickness of 90 to 160 ⁇ m and a width of 230 mm is used.
  • the intermediate transfer belt 33 preferably has a volume resistivity of 10 8 to 10 11 ⁇ *cm and a surface resistivity of 10 8 to 10 11 ⁇ /sq under an environment of 23° C. and 50% RH.
  • the intermediate transfer belt 33 acquires an electrical charge, which requires an additional process to set the voltage value downstream in the image forming process higher. Accordingly, it becomes impossible to use a single power supply to the primary transfer unit. This is because, due to the electrical discharge that occurs in the transfer process or the transfer medium separation process, the electrical potential of the surface of the intermediate transfer belt 33 becomes high and the self-discharge from the surface of the intermediate transfer belt 33 becomes impossible.
  • volume resistivity and the surface resistivity are below the above defined ranges, the decrease of the charged potential starts earlier, which is favorable to the self-discharge, but because the current in the transfer process flows over a surface of the photoreceptor, toner dispersion may occur.
  • a specular-type or diffusion-type toner mark sensor 17 (TM sensor) is disposed in the downstream of the lowermost process unit 21 .
  • the sensor 17 measures density of the toner image or position of each color on the intermediate transfer belt 33 .
  • the secondary transfer roller 36 as a rotary transfer member is disposed at a position opposed to the drive roller 31 via the intermediate transfer belt 36 .
  • the secondary transfer roller 36 presses against an external surface of the intermediate transfer belt 33 and a secondary transfer nip is formed at a position where the secondary transfer roller 36 contacts the intermediate transfer belt 33 around which the secondary transfer roller 26 and the drive roller 31 are stretched.
  • the secondary transfer roller 36 includes a metal core formed of a metal such as SUS, which is coated by an elastic member such as urethane with an adjusted resistivity of from 10 6 to 10 10 ⁇ .
  • elastic materials include ion-conductive roller (formed of urethane with dispersed carbon, NBR, or hydrin) or electroconductive type roller (formed of EPDM).
  • a roller with Asker C hardness from 35 to 50 may be used.
  • the resistivity of the secondary transfer roller 36 is below the defined range, transferability between the image formed of multicolor (e.g., three-color superposed image) and the monochrome image existing in the same image cannot be ensured. This is because resistivity of the secondary transfer roller 36 is small, and therefore enough current flows to transfer the monochrome image at a relatively low voltage. However, because a higher voltage than the voltage appropriate to transfer the monochrome image is required to transfer the multi-color image, if the voltage is set at the multicolor image transferable voltage, an excessive transfer current flows for the monochrome image, thereby reducing the transferring efficiency.
  • multicolor e.g., three-color superposed image
  • the above resistivity values are obtained as follows: 1) the roller 36 is placed on a conductive metal plate, 2) a load of 4.9 N is applied to each of both ends of the metal core, 3) voltage of 1 kV is applied between the metal core and the metal plate, and 4) current value is calculated.
  • a waste toner container 37 is disposed to contain the waste toner which is removed by the belt cleaning unit 34 and conveyed via a waste toner conveying hose, not shown.
  • the sheet feed unit 4 is disposed at a bottom of the image forming apparatus 1 and includes a sheet feed tray 41 containing a recording sheet P as a recording medium and a sheet feed roller 42 to feed the recording sheet P from the sheet feed tray 41 .
  • the conveyance path 5 is a path through which the recording sheet P fed out of the sheet feed unit 4 is conveyed and a pair of registration rollers 51 , a conveyance roller pair, not shown, up to an ejection portion which will be described later are arbitrarily disposed along the conveyance path 5 .
  • the fixing unit 6 is disposed downstream in the conveyance path of the secondary transfer nip and includes a fixing roller heated by a heat source, not shown, a pressure roller capable of pressing the fixing roller, and the like.
  • the ejection portion is disposed most downstream of the conveyance path 5 of the image forming apparatus 1 , and includes a pair of sheet ejection rollers to eject the recording sheet P outside and a sheet ejection tray to stock the ejected sheet.
  • each photoreceptor 22 of each process unit 21 is driven to rotate in the clockwise direction as illustrated in FIG. 1 at a cyclic speed of 100 to 180 mm/s, and each surface of the photoreceptor 22 is uniformly charged to a predetermined polarity and surface potential of, for example, ⁇ 200V to ⁇ 1000V by the charging roller 23 .
  • the charged surface of each photoreceptor drum 22 is irradiated the laser beams L for each color component of the target image from the exposure unit, thereby creating an electrostatic latent image thereon.
  • the image data exposed on each photoreceptor 22 is monochrome image data decomposed, from the target full-color image, into color data of yellow, magenta, cyan, and black.
  • Each developing device 24 supplies toner to the electrostatic latent image thus formed on each photoreceptor 22 , and the electrostatic latent image is rendered visible as a toner image or a developer image.
  • the intermediate transfer belt 33 is driven to rotate in a direction as indicated by an arrow in FIG. 1 .
  • a constant voltage or constant-current controlled voltage e.g., +500 to +1000V
  • a transfer electrical field is formed at a primary transfer nip between each primary transfer roller 35 and each photoreceptor drum 22 .
  • the toner image of each color formed on each photoreceptor drum 22 of each process unit 21 is sequentially transferred in a superposed manner on the intermediate transfer belt 33 by the transfer electrical field formed in the primary transfer nip. With the operation above, a full-color toner image is formed on the surface of the intermediate transfer belt 33 .
  • the toner remaining on each surface of the photoreceptor drum 22 after transferring the toner image is removed by the cleaning blade 25 .
  • the photoreceptor drum surface is subjected to a discharging operation by a discharger, not shown, the surface potential is initialized, and then, a next image forming is to be performed.
  • the sheet feed roller 42 of the sheet feed unit 4 is driven to rotate, so that the recording sheet P contained in the sheet feed tray 41 is fed out to the conveyance path 5 .
  • the recording sheet P is conveyed to the secondary transfer nip between the secondary transfer roller 36 and the drive roller 31 opposed to the secondary transfer roller 36 at a matched timing obtained by the registration rollers 51 .
  • the transfer voltage having a polarity opposite to that of the charged toner of the toner image on the intermediate transfer belt 33 is applied to the secondary transfer roller 36 , a transfer electrical field is formed at the secondary transfer nip. Through the electrical field formed at the secondary transfer nip, the toner image on the intermediate transfer belt 33 is transferred en bloc to the recording sheet P.
  • the recording sheet P on which a toner image has been transferred is conveyed to the fixing unit 6 , the recording sheet P is heated and pressed by the heated fixing roller and the pressure roller, and the toner image is fixed onto the recording sheet P. Thereafter, the recording sheet P is separated from the fixing roller, is conveyed by a pair of conveyance rollers, not shown, to the ejection portion, and is ejected by the sheet ejection roller to the sheet ejection tray.
  • the remaining toner attached on the intermediate transfer belt 33 after transferring process is removed by the belt cleaning unit 34 , is conveyed via a screw and a waste toner conveying hose, both not shown, to the waste toner container 37 and is collected therein.
  • FIGS. 2A and 2B each are a side view illustrating a general structure of a part around the secondary transfer nip in the image forming apparatus 1 .
  • the secondary transfer roller 36 to form the secondary transfer nip is rotatably supported to a housing 7 .
  • a spring 36 a e.g., a compression spring configured to press the secondary transfer roller 36 against the drive roller 31 to obtain a predetermined nip pressure is disposed between the housing 7 and the secondary transfer roller 36 .
  • the housing 7 is disposed to cover a side of the conveyance path 5 and rotatably attached to a member 1 a of a stationary side (for example, a base frame) attached to the apparatus body so as to rotate about a first rotary center O 1 .
  • a cover, not shown, of an external case of the image forming apparatus 1 is opened, the housing 7 is further rotated in direction of the arrow, and the side space of the conveyance path 5 is released.
  • the secondary transfer roller 36 when the housing 7 is rotated in the direction of the arrow, the secondary transfer roller 36 , following the rotation of the housing 7 , moves in a backward direction from the drive roller 31 and the secondary transfer nip is eliminated.
  • the secondary transfer roller 36 is disposed at a position contacting the intermediate transfer belt 33 , thereby forming the secondary transfer nip.
  • a state in which the housing 7 is closed and the secondary transfer nip is formed is referred to as a closed state of the housing (shown by a solid line in FIG. 1 ), and a state in which the housing 7 is opened and the secondary transfer nip is eliminated is called an open state of the housing (shown by a broken line in FIG. 1 ).
  • a guide unit 70 to guide the recording sheet P to be conveyed via the conveyance path 5 is disposed around the secondary transfer nip.
  • the guide unit 70 includes a guide member 71 to guide the recording sheet P in the conveyance direction at an upstream of the secondary transfer nip in the sheet conveyance direction, a receiving part 39 to adjust positioning of the guide member 71 , and a biasing spring 72 to bias the guide member 71 as a biasing means.
  • the guide unit 70 according to the present embodiment includes a stopper 73 capable of contacting the guide member 71 , and a rotary sliding unit 75 which allows a rotary movement and a back-and-forth sliding movement between the guide member 71 and the housing 71 relatively.
  • the guide member 71 has a width larger than that of the maximum-sized recording sheet P among the recording sheet P to be used.
  • the guide member 71 is formed of resins, for example.
  • the guide member 71 can be formed of any metal such as stainless steel (SUS).
  • a guide portion 71 a to guide the recording sheet P is formed at a central portion of the axis direction thereof.
  • the axis direction means a direction the first rotary center O 1 extends, which is applied to the description below.
  • Contact portions 71 b to contact the receiving portion 39 or the positioning member 38 are disposed at both lateral ends of the axial direction of the guide member 71 .
  • At least the front surface of the contact portion 71 b is formed into a curved surface (or a cylindrical surface).
  • a support shaft 71 c protruding in the shaft direction is formed at another end of the guide member 71 .
  • the biasing spring 72 is disposed between the housing 7 and the guide member 71 .
  • the biasing spring 72 is kept in the tension state and one end of the biasing spring 72 is connected at a part between the contact portion 71 b of the guide member 71 and the support shaft 71 c .
  • a biasing force F as illustrated by an arrow in FIGS. 2A and 2B is constantly applied.
  • the biasing force F is preferably exerted in a direction parallel to a slidable moving direction allowed between the housing 7 and the guide member 71 in the rotary sliding unit 75 , which will be described later.
  • the biasing force F should only be a rotation moment in the direction to rotate the guide member 71 about the one end of the guide member 71 . So long as such a rotation moment is given to the guide member 71 , the biasing spring 72 can be disposed at any arbitrary position. In addition, the biasing force F can be achieved by use of the spring in the compressed state as the biasing spring 72 . Alternatively, the biasing force F can be achieved by use of an arbitrary elastic member other than the spring.
  • the receiving part 39 is integrated into a support frame 40 configured to rotatably support the drive roller 31 and the driven roller 32 .
  • the receiving part 39 in FIG. 2A includes a V-shaped partial cutout at a surface opposite the housing 7 .
  • the support frame 40 is formed from resins by injection molding and the receiving part 39 is formed by injection molding at the same time.
  • the support frame 40 is attached to a stationary member (such as a base frame) of the apparatus body and disposed at both sides in the shaft direction of the drive roller 31 and the driven roller 32 .
  • the drive roller 31 and the driven roller 32 are sandwiched between the support frame 40 .
  • each of the rotary shaft 31 a and 32 b of the drive roller 31 and the driven roller 32 is rotatably supported via a shaft bearing such as a roller bearing, not shown.
  • the receiving part 39 includes two guide surfaces 38 a and 38 b , both of which guide the contact portion 71 b of the guide member 71 .
  • One guide surface 38 a (the first guide surface) of the receiving part 39 extends in a direction intersecting the direction of the biasing force F and another guide surface 38 b (the second guide surface) extends in a direction substantially parallel to the direction of the biasing force F.
  • Both guide surfaces 38 a and 38 b are flat.
  • a corner connecting the two guide surfaces 38 a and 38 b functions as a positioning part 38 c so as to position the guide member 71 .
  • the positioning member 38 as illustrated in FIG. 2B is disposed at both sides in the shaft direction of the drive roller 31 with the drive roller 31 sandwiched between, so that the contact portion 71 b of the guide member 71 may contact the positioning member 38 .
  • the positioning member 38 has a plate shape formed of a metal material similar to the guide member 71 (such as stainless steel) and is fixed to the stationary member supporting a drive shaft 31 a of the drive roller 31 .
  • the positioning member 38 in FIG. 2B includes a V-shaped receiving part 39 formed of two guide surfaces 38 a and 38 b both of which guide the contact portion 71 b of the guide member 71 .
  • One guide surface 38 a (the first guide surface) of the receiving part 39 extends in a direction intersecting the direction of the biasing force F and another guide surface 38 b (the second guide surface) extends in a direction substantially parallel to the direction of the biasing force F.
  • Both guide surfaces 38 a and 38 b are formed to have a flat surface.
  • a corner connecting the two guide surfaces 38 a and 38 b functions as a positioning part 38 c so as to position the guide member 71 .
  • the guide portion 71 a of the guide member 71 is disposed upstream in the direction of rotation of the intermediate transfer belt 33 than the starting point of the secondary transfer nip and disposed with a predetermined interval with a peripheral surface of the intermediate transfer belt 33 .
  • the recording medium P conveyed through the conveyance path 5 first contacts the guide member 71 , is guided by the guide portion 71 a , and contacts the peripheral surface of the intermediate transfer belt 33 at upstream in the direction of rotation of the intermediate transfer belt 33 than the starting point of the secondary transfer nip.
  • the stopper 73 is fixed to the housing 7 at an area in which the biasing force F is acted than the guide member 71 . As illustrated in FIGS. 2A and 2B , in a state in which the housing 7 is closed and the guide member 71 is positioned at the positioning part 38 c , the stopper 73 is not contacted to the guide member 71 .
  • the rotary sliding unit 75 is formed such that the support shaft 71 c of the guide member 71 is slidably engaged with a slot 74 formed in the housing 7 .
  • the guide member 71 is rotatable about the support shaft 71 c with respect to the housing 7 and a rotation center O 2 (as a second rotation center) of the support shaft 71 c becomes slidable back and force within a predetermined range S with respect to the housing 7 .
  • one end of the slidable range S is a position where the support shaft 71 c (shown by a solid line) contacts one edge of the slot 74 existing in a direction of action of the biasing force F.
  • the support shaft 71 c (shown by a broken line) is made non-contact to the other edge 74 b of the slot 74 .
  • each part of the guide unit 70 in the closed state of the housing 7 , is configured such that the second rotation center O 2 is positioned within the range S (that is, the support shaft 71 c is in the non-contact state to both edges 74 a and 74 b of the slot 74 ).
  • the structure of the rotary sliding unit 75 is not limited to the structure as exemplified in FIGS. 2A and 2B , but any structure can be adopted so long as a relative rotational and slidable movement between the guide member 71 and the housing 7 is allowed.
  • a part corresponding to the support shaft 71 c can be disposed on the housing 7 and a part corresponding to the slot 74 can be disposed on the guide member 71 .
  • a construction in which a guide rail and a member sliding along the guide rail are disposed and one end of the guide member 71 is rotatably attached to the sliding member can be adopted.
  • the range S be disposed linearly as illustrated in the drawings, but may be formed into a curve by configuring the slot 74 to be in a curved shape so long as the slidable movement can be smoothly performed. To enable a smooth slidable movement, no step is formed in the range S.
  • the guide member 71 rotates in the counterclockwise direction about the second rotation center O 2 by the biasing force F of the biasing spring 72 and abuts the stopper 73 .
  • the entire guide member 71 slidably moves in the direction of the action of the biasing force F
  • the support shaft 71 c contacts one edge 74 a of the slot 74
  • second rotation center O 2 reaches one end of the range S.
  • the contact portion 71 b of the guide member 71 slidably moves downward on the first guide surface 38 a of the receiving part 39 .
  • the housing 7 When the housing 7 is moved to further open, the contact portion 71 b of the guide member 71 is separated from the first guide surface 38 a .
  • the guide member 71 contacts the stopper 73 and in a state in which the second rotation center O 2 is remained at the end of the slidable range S, the housing 7 becomes an open state as illustrated in FIGS. 5A and 5B .
  • the contact portion 71 b of the guide member 71 contacts the first guide surface 38 a of the receiving part 39 (or the positioning member 38 ) as illustrated in FIGS. 6A and 6B .
  • the angle ⁇ 3 of the guide member 71 formed with the first guide surface 38 a is an acute angle.
  • the contact portion 71 b of the guide member 71 slidably moves upward along the first guide surface 38 a .
  • the guide member 71 rotates in the clockwise direction about the second rotation center O 2 by the biasing force F of the biasing spring 72 and is separated from the stopper 73 .
  • the guide unit 70 because the recording medium P is guided by the guide member 71 at an upstream of the direction of rotation of the intermediate transfer belt 33 than the secondary transfer nip, formation of the space (serving as an electrical discharge area) between the intermediate transfer belt 33 and the recording sheet P near the secondary transfer electrical field is prevented.
  • the image quality can be improved.
  • the guide member 71 is supported by the housing 7 , the guide member 71 is moved following the opening and closing of the housing 7 .
  • the guide member 71 can be evacuated from the periphery of the conveyance path 5 of the recording sheet P in the open state of the housing 7 . Therefore, when the recording sheet P clogging and remaining in the conveyance path 5 is removed therefrom, an interference of the sheet with the guide member 71 can be prevented, thereby improving the workability in the maintenance work.
  • the receiving part 39 When the receiving part 39 is formed as a member separated from the support frame 40 as illustrated in FIGS. 2B , 4 B, 5 B, 6 B, 7 B, 9 B, 10 B, and 12 B and is configured to be attached to the support frame 40 or any other member, precision in mounting the receiving part 39 may affect the positional precision of the guide member 71 . In this case, cumulative errors may reduce the positional precision of the guide member 71 with respect to the intermediate transfer belt 33 . To deal with the concern, in the invention as illustrated in FIGS. 2A , 4 A, 5 A, 6 A, 7 A, 9 A, 10 A, 11 , 12 A and the like, the receiving part 39 is directly formed to the support frame 40 , so that the mounting precision of the receiving part 39 can be canceled.
  • the support frame 40 supports the intermediate transfer belt 33 via the drive roller 31 and the driven roller 32 .
  • the precision in the mounting of the guide member 71 to the intermediate transfer belt 33 can be improved, thereby enabling to prevent image disturbance due to the electrical discharge.
  • tolerance of the gap between the intermediate transfer belt 33 and the positioned guide member 71 is affected by each tolerance of a distance between an interior surface of the support frame 40 being an engagement surface of the bearing and the support frame 40 to the positioning part 38 c ; an external diameter of the drive roller 31 ; and the thickness of the intermediate transfer belt 33 .
  • the tolerance of the gap has no relation to the mounting precision of the receiving part 39 , the above effect can obtained.
  • the guide member 71 disposed on the housing 7 is positioned by the receiving part 39 disposed on the apparatus body, securing an introducing and evacuating path of the guide member 71 necessary to introduce or evacuate the guide member 71 to and from the positioning part 38 c is difficult.
  • the guide member 71 is rotatably attached to the housing 7 and a back and forth slidable movement between the guide member 71 and the housing 7 is allowed, flexibility of the posture of the guide member 71 with respect to the housing 7 is improved.
  • the guide member 70 is configured such that the second rotation center O 2 is positioned within the slidable range S in the closed state of the housing 7 , the slidable movement of the guide member 71 is allowed between the housing 7 and the guide member 71 in both directions and the flexible posture of the guide member 71 with respect to the housing 7 is ensured. Then, the housing 7 can be opened smoothly.
  • the guide member 70 is configured such that when the guide member 71 contacts the stopper 73 , the second rotation center O 2 is positioned at the end of the slidable range S.
  • the housing 7 rotates in a state in which the posture of the guide member 71 is held with respect to the housing 7 . Accordingly, during the rotation of the housing 7 , the movement locus of the guide member 71 is constant regardless whether the housing is opening or closing. Accordingly, contacts or interference of the guide member 71 with other peripheral parts (in particular, with the parts on the side of the apparatus body) can be prevented, thereby making the design of the peripheral structure easier.
  • the contact portion 71 b of the guide member 71 is disposed at a non-printing area at the front end of the guide member 71 , the contact portion 71 b of the guide member 71 can be slidably contacted in the non-printing area. Accordingly, when friction particles are generated due to the slidable contact, they do not easily attach to the recording sheet P, thereby preventing degradation of the image quality due to the deposition of the friction particles.
  • both the guide member 71 and the receiving part 39 are formed from resin materials so as to retard abrasion between the guide member 71 and the receiving part 39 to be concerned when both are made from different materials. It can be configured such that the body of the guide member 71 is made of a metal material and only a slidable part thereof may be attached with a cover made of resins (see FIG. 13A ). To retard abrasion, the support frame 40 and the guide member 71 are preferably formed of the same material. Even if either one of the support frame 40 or the guide member 71 is formed of a metal material, the other is also preferably formed of the metal. In the example as illustrated in FIG.
  • both members are formed of a metal material. Both may be formed of a metal material but also of resins. Accordingly, the abrasion of both members can be prevented similarly.
  • a vertical axis shows evaluation of the image disturbance in 5 levels and a horizontal axis shows a distance D.
  • occurrence of the image disturbance is lowered and image quality improves.
  • the distance D becomes larger, the image quality improves.
  • the distance D of 1.5 mm or more is secured, occurrence of the image disturbance can be substantially prevented. It is therefore recommended that the guide member 71 is positioned by the positioning part 38 c so that the distance D becomes 1.5 mm or more.
  • the image disturbance due to the electrical discharge tends to occur in an environmental condition of low temperature and low humidity and in a state in which the electrical resistance is high at a time of printing on a second surface in the duplex printing.
  • the thick sheet is not necessarily guided toward upstream in the direction of rotation of the intermediate transfer belt 33 from the secondary transfer nip.
  • the thick sheet P guided toward upstream exceeding the requirement receives a greater load from the guide member 71 , the conveyance speed is not stabilized and there is also a problem of fluctuation in the image scaling and the density.
  • the guide direction by the guide member 71 be made variable corresponding to the pressing force due to the rigidity of each recording sheet P.
  • the guide member 71 is elastically supported by the biasing spring 72 and is slidably supported by the rotary sliding unit 75 in the direction of the biasing force F.
  • the guide member 71 that receives a pressing force B from the recording sheet P displaces in the direction of the pressing force B against the biasing force F.
  • the pressing force B increases in proportion to a weight of the sheet.
  • the guide member 71 displaces, the recording sheet P with a high rigidity is guided toward a direction approaching the entrance of the secondary transfer nip than the guided direction by the guide member 71 before displacement. Accordingly, even if the recording sheet P reaches the secondary transfer nip, the recording sheet P is not greatly bent by the guide member 71 , thereby reducing the conveyance load and stabilizing the conveyance speed.
  • the contact portion 71 b of the guide member 71 slides along the second guide surface 38 b of the receiving part 39 .
  • the position of the contact portion 71 b of the guide member 71 can be controlled and the guided direction of the recording sheet P does not become unstable even though the guide member 71 displaces as described above.
  • the guide member 71 does not displace.
  • the recording sheet P with a low rigidity is guided toward upstream in the rotation direction of the intermediate transfer belt 33 than the electrical discharge area between the drive roller 31 and the secondary transfer roller 36 and strikes in the secondary transfer nip winding around the external surface of the intermediate transfer belt 33 after contacting the intermediate transfer belt 33 . Accordingly, the image disturbance due to electrical discharge does not easily occur even in a state where the electrical resistance is high at a time of printing on a second surface in the duplex printing.
  • the biasing force F of the biasing spring 72 is to be stronger than the pressing force B of the recording sheet P.
  • the biasing force of the biasing spring 72 is set to F and the pressing force of the sheet with a maximum weight, among the recording sheet P specified to be applicable to the duplex printing, applied to the guide member 71 is set to Fa, a relation of Fa ⁇ F should be realized.
  • the pressing force B should be stronger than the biasing force F.
  • the pressing force of the recording sheet P incompatible with the duplex printing is set to Fb, a relation of F ⁇ Fb should be realized.
  • a stopper 76 regulating the maximum displacement of the guide member 71 displaced by a contact with the recording sheet P may be disposed on the housing 7 (or on a member at a side of the apparatus body) as illustrated by a broken line in FIGS. 9A and 9B .
  • the stopper 76 prevents the guide member 71 from forwarding to the secondary transfer roller 36 exceeding the entrance to the secondary transfer nip.
  • the intersecting angle ( ⁇ 1 + ⁇ 2 ) formed between the first guide surface 38 a and the second guide surface 38 b of the receiving part 39 can be acute as illustrated in FIG. 18 . Accordingly, the positioning effect of the guide member 71 with respect to the positioning part 38 c is improved, thereby enabling to position the guide member 71 with a higher precision. In this case, even if the elastic force of the biasing spring 72 is lowered compared to the embodiment as illustrated in FIG. 2 , a sufficient effect can be obtained.
  • the guide member 71 When the guide member 71 is formed of a metal, the guide member 71 is formed from the metal plate (with a thickness of from 0.8 to 1.5 mm) which is subjected to the press working. In this case, when the guide member 71 contacting the recording sheet P is bent, the guiding function of the guide portion 71 a is not stable in the shaft direction, thereby degrading the image quality. To prevent this, as illustrated in FIGS. 10A and 10B , a front end of the guide member 71 , in particular, the guide portion 71 a is machined into a round shape, for example, to increase the rigidity of the guide portion 71 a . If necessary, the contact portion 71 b as well as the guide portion 71 a may be bent.
  • contact portion 71 b is remained as a sheared surface in the press work, burr of the sheared surface may cause abrasion of the receiving part 39 to be promoted.
  • burr of the sheared surface may cause abrasion of the receiving part 39 to be promoted.
  • the contact portion 71 b is formed into a round shape, such a disadvantage as described above can be prevented.
  • the guide portion 71 a and the contact portion 71 b at a front end of the guide member 71 may be subjected to lower friction treatment (as indicated by a broken line) such as a fluorine resin coating as illustrated in FIG. 11 . Accordingly, friction between the guide portion 71 a and the recording sheet P can be decreased, and further, because the contact portion 71 b and the receiving part 39 contact smoothly, slidability is improved, thereby minimizing abrasion between the two parts.
  • the guide portion 71 a of the guide member 71 can be formed by a roller 71 d as illustrated in FIGS. 12A and 12B . With this structure, the sliding load between the guide member 71 and the recording sheet P can be reduced and the recording sheet P can be conveyed to the secondary transfer nip stably.
  • the contact portion 71 b of the guide member 71 and the receiving part 39 configured to position the guide member 71 each are formed into a curved surface (or a cylindrical surface), convex in the case of the former and concave in the case of the latter.
  • the curvature radius R 1 of the receiving part 39 is made greater than the curvature radius R 2 of the guide member 71 .
  • the convex-surface-shaped contact portion 71 b of the guide member 71 is covered by a resin-made cover 71 e at both ends of the front end of the guide member 71 in the axial direction.
  • the guide portion 71 a of the guide member 71 is machined (not shown) as illustrated in FIGS. 10A and 10B .
  • the concave-surface-shaped receiving part 39 is integrated into the resin-made support frame 40 configured to rotatably support the drive roller 31 and the driven roller 32 .
  • the mounting precision of the receiving part 39 is canceled and the precision in the mounting of the guide member 71 to the intermediate transfer belt 33 is improved, thereby enabling prevention of the image disturbance due to the electrical discharge.
  • the receiving part 39 is formed to any member other than the support frame 40 (for example, the positioning member 38 )
  • the mounting precision of the other member with respect to the apparatus body member affects the mounting precision of the guide member 71 by the receiving part 39 .
  • the support frame 40 when the receiving part 39 is formed to the positioning member 38 is preferably formed of resin materials similarly to the case of the cover 71 e serving as a contact portion 71 b .
  • the whole part of the guide member 71 can be formed of a metal material excluding the cover 71 e .
  • the cover 71 e can be formed of a metal material.
  • the support frame 40 is also formed of the metal material.
  • the guide unit 70 similar to the one in the embodiment as illustrated in FIGS. 2A and 2B is disposed. Accordingly, similar to the embodiment as illustrated in FIGS. 2A and 2B , in the open state of the housing 7 , the guide member 71 is pressed against the receiving part 39 by the biasing force F of the biasing spring 72 and positioning of the guide member 71 is performed.
  • FIG. 13B is an enlarged view of a part in FIG. 13A .
  • the guide member 71 slidably moves sliding along an interior surface of the receiving part 39 similarly to the aspect as illustrated in FIGS. 3A to 3C through 7 A and 7 B. Because the receiving part 39 and the contact portion 71 b each are formed into a curved surface, butting during the slidably moving of both parts does not occur easily and the housing 7 can be opened and closed smoothly.
  • the guide member 71 When the guide member 71 contacts the high rigidity recording sheet P such as a thick sheet, the guide member 71 that receives a pressing force from the recording sheet P slides along the receiving part 39 and displaces in the slidable movement direction of the guide unit 70 as illustrated by a broken line in FIG. 13B . (At this time, the support shaft 71 c also moves in the same direction along the slot 74 .) As a result, the recording sheet P is guided to approach the entrance of the secondary transfer nip than the guided direction by the guide member 71 before displacement. Accordingly, even if the recording sheet P with a higher rigidity reaches the secondary transfer nip, the recording sheet P is not greatly bent by the guide member 71 , thereby reducing the conveyance load and stabilizing the conveyance speed.
  • the curved-surface receiving part 39 also includes each part 38 a , 38 b , and 38 c , and functions similarly.
  • FIG. 14 is a side view illustrating a general structure of a part around the secondary transfer nip according to another embodiment of the present invention.
  • the guide unit 70 does not include the rotary sliding unit 75 which allows a relative rotary movement and back-and-forth sliding movement between the guide member 71 and the housing 7 among components as illustrated in FIG. 2A .
  • the guide member 71 is supported by the housing 7 via a supporting and biasing spring 75 a as a biasing means, which is different from the embodiment as illustrated in FIG. 2A .
  • a supporting and biasing spring 75 a as a biasing means
  • the supporting and biasing spring 75 a is a compression spring disposed between the housing 7 and the guide member 71 and biases constantly the guide member 71 from its base end to the front end.
  • the contact portion 71 b of the guide member 71 contacts the positioning part 38 c of the receiving part 39 and the contact portion 71 b is positioned at the positioning part 38 c by the biasing force of the supporting and biasing spring 75 a .
  • the recording medium P contacting the guide member 71 is guided by the guide member 71 toward upstream in the rotation direction of the intermediate transfer belt 33 than the secondary transfer nip and the degradation of the image quality by the electrical discharge can be prevented.
  • the contact portion 71 b of the guide member 71 is separated from the receiving part 39 while sliding along the second guide surface 38 b .
  • the contact portion 71 b of the guide member 71 slidably moves along the second guide surface 38 b and reaches the positioning part 38 c and is positioned.
  • the supporting and biasing spring 75 a is compressed according to the rotation of the housing 7 in the closing direction until the housing 7 is completely closed. Accordingly, in the completely closed state of the housing 7 , the guide member 71 is positioned at the positioning part 38 c by the biasing force of the supporting and biasing spring 75 a.
  • the guide member 71 flies out toward the direction biased by the supporting and biasing spring 75 a and contacts the intermediate transfer belt 33 , which may cause the intermediate transfer belt 33 to be damaged.
  • the guide member 71 If the flying out of the guide member 71 occurs excessively by the biasing force, the guide member 71 interferes with the edge surface of the support frame 40 when the housing 7 is closed from the open state and it may occur that the guide member 71 is not guided to the receiving part 39 . To prevent this, it is preferred that a stopper to prevent the guide member 71 from flying out be disposed between the guide member 71 and the housing 7 .
  • FIGS. 16A to 16C shows an example of the stopper 76 disposed to the housing 7 .
  • the guide member 71 includes an engagement part 71 g capable of engaging with the stopper 76 in the biasing direction of the supporting and biasing spring 75 a .
  • the guide member 71 includes the engagement part 71 g which is formed with a protruding portion 71 h as illustrated in FIG. 16C .
  • the engagement part 71 g can also be configured such that a cutout portion 71 i is formed to the guide member 71 .
  • the image forming apparatus may also be applied to the monochrome image forming apparatus, any other type of copier, printer, facsimile machine, or the multifunction apparatus combining the functions of the above devices.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Electrostatic Charge, Transfer And Separation In Electrography (AREA)
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6132133B2 (ja) 2012-07-05 2017-05-24 株式会社リコー ユニット落下防止機構及び画像形成装置
US9164470B2 (en) * 2012-09-18 2015-10-20 Ricoh Company, Limited Transfer device and attachment of the transfer device to a cover of an image forming apparatus
JP6094174B2 (ja) 2012-11-28 2017-03-15 株式会社リコー トナー回収装置およびこれを有する画像形成装置
JP2015161914A (ja) 2014-02-28 2015-09-07 株式会社リコー 画像形成装置
JP6436383B2 (ja) * 2014-11-13 2018-12-12 株式会社リコー 転写装置及び画像形成装置
US9958806B2 (en) 2015-11-25 2018-05-01 Ricoh Company, Ltd. Developing device and image forming apparatus incorporating same
JP7039878B2 (ja) * 2017-07-28 2022-03-23 セイコーエプソン株式会社 印刷装置
JP2021179487A (ja) * 2020-05-12 2021-11-18 キヤノン株式会社 定着装置
JP2022066945A (ja) 2020-10-19 2022-05-02 株式会社リコー シート搬送装置及び画像形成装置

Citations (45)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04291362A (ja) 1991-03-20 1992-10-15 Konica Corp 画像形成装置
US5245394A (en) 1991-03-20 1993-09-14 Konica Corporation Image forming apparatus having an openable conveyance path
JPH05257346A (ja) 1992-03-16 1993-10-08 Konica Corp 給紙ガイド装置
JPH09240880A (ja) 1996-03-11 1997-09-16 Minolta Co Ltd 転写前ガイド装置
US5983062A (en) 1997-04-18 1999-11-09 Canon Kabushiki Kaisha Image forming apparatus with shifting means to position image transfer unit
JP2001356538A (ja) 1999-10-29 2001-12-26 Ricoh Co Ltd 画像形成装置、転写材搬送方法及び転写装置
JP2001356619A (ja) 2000-06-15 2001-12-26 Matsushita Electric Ind Co Ltd 転写装置
JP2002040818A (ja) 2000-07-26 2002-02-06 Ricoh Co Ltd 画像形成装置
JP2002214943A (ja) 2001-01-23 2002-07-31 Ricoh Co Ltd 画像形成装置
JP2003307944A (ja) 2002-04-18 2003-10-31 Canon Inc 画像形成装置
CN1700119A (zh) 2004-05-18 2005-11-23 京瓷美达株式会社 图像形成装置
JP2006011044A (ja) 2004-06-25 2006-01-12 Fuji Xerox Co Ltd 画像形成装置
JP2006248663A (ja) 2005-03-09 2006-09-21 Canon Inc シート搬送装置及び画像形成装置
JP2006301509A (ja) 2005-04-25 2006-11-02 Konica Minolta Business Technologies Inc 画像形成装置
US20070008397A1 (en) * 2005-07-08 2007-01-11 Canon Kabushiki Kaisha Image Forming Apparatus
US20070110458A1 (en) 2005-11-15 2007-05-17 Tomofumi Inoue Dust container and image forming apparatus
US20070183816A1 (en) 2006-01-30 2007-08-09 Kohji Hatayama Transfer device and image forming apparatus including the same
US20070269233A1 (en) 2006-05-19 2007-11-22 Takeshi Sakashita Image forming apparatus
US20080003022A1 (en) 2006-06-28 2008-01-03 Takeshi Sakashita Transfer device and image forming apparatus
JP2008003447A (ja) 2006-06-26 2008-01-10 Konica Minolta Business Technologies Inc 画像形成装置
JP2008026533A (ja) 2006-07-20 2008-02-07 Kyocera Mita Corp 画像形成装置
US20080028967A1 (en) 2006-06-12 2008-02-07 Takeshi Sakashita Image forming apparatus
US20080050158A1 (en) 2006-08-23 2008-02-28 Kohji Hatayama Power guiding device and image forming apparatus having power guiding device
US20080138133A1 (en) 2006-12-08 2008-06-12 Ricoh Company, Limited Transfer device, image forming apparatus, and waste toner container
US20080187365A1 (en) 2007-02-05 2008-08-07 Ricoh Company, Limited Image forming apparatus and powder housing unit
US20080193173A1 (en) 2007-02-09 2008-08-14 Ricoh Company, Limited Belt unit, transfer belt unit, and image forming apparatus
US20080193167A1 (en) 2007-01-16 2008-08-14 Ricoh Company, Limited Powder container and image forming apparatus
US20080226358A1 (en) 2007-03-13 2008-09-18 Ricoh Company, Limited Image forming apparatus
US20080310893A1 (en) 2007-06-18 2008-12-18 Tomoya Adachi Transfer device and image forming apparatus
US20080316559A1 (en) 2007-06-19 2008-12-25 Konica Minolta Business Technologies, Inc. Laser scanning device and image forming apparatus
US20080317532A1 (en) * 2007-06-25 2008-12-25 Ricoh Company, Ltd. Image forming apparatus
US20080317521A1 (en) 2007-06-22 2008-12-25 Tomofumi Inoue Transfer belt device, method of assembling the same, and image forming apparatus
CN101334620A (zh) 2007-06-25 2008-12-31 株式会社理光 图像形成装置
US20090011882A1 (en) 2007-07-03 2009-01-08 Mitsutoshi Kichise Belt unit and image forming apparatus
US20090016772A1 (en) 2007-07-13 2009-01-15 Tomoya Adachi Belt device and image forming apparatus
US20090014288A1 (en) 2007-07-13 2009-01-15 Takafumi Miyazaki Belt device and image forming apparatus
US20090123201A1 (en) 2007-11-13 2009-05-14 Masanao Ehara Image forming apparatus
US20090129831A1 (en) 2007-11-21 2009-05-21 Takeshi Sakashita Transfer device and image forming apparatus
US20090162114A1 (en) * 2007-12-17 2009-06-25 Makoto Nakura Contacting and separating mechanism and image forming apparatus
US20090285594A1 (en) 2007-12-27 2009-11-19 Mitsutoshi Kichise Image forming apparatus
US20100239334A1 (en) 2008-02-18 2010-09-23 Ricoh Company, Ltd. Image forming apparatus
US20110110685A1 (en) 2009-11-10 2011-05-12 Fuji Xerox Co., Ltd. Image forming apparatus and apparatus exterior unit
US20120057908A1 (en) 2010-09-07 2012-03-08 Ricoh Company, Ltd. Belt unit, transfer unit including the belt unit, and image forming apparatus including the transfer unit
US20120114373A1 (en) 2010-11-08 2012-05-10 Ricoh Company, Ltd. Image forming apparatus capable of effectively utilizing interior space
US20130216260A1 (en) * 2012-02-21 2013-08-22 Seiichi Kogure Image forming apparatus

Patent Citations (48)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04291362A (ja) 1991-03-20 1992-10-15 Konica Corp 画像形成装置
US5245394A (en) 1991-03-20 1993-09-14 Konica Corporation Image forming apparatus having an openable conveyance path
JPH05257346A (ja) 1992-03-16 1993-10-08 Konica Corp 給紙ガイド装置
JPH09240880A (ja) 1996-03-11 1997-09-16 Minolta Co Ltd 転写前ガイド装置
US5983062A (en) 1997-04-18 1999-11-09 Canon Kabushiki Kaisha Image forming apparatus with shifting means to position image transfer unit
JP2001356538A (ja) 1999-10-29 2001-12-26 Ricoh Co Ltd 画像形成装置、転写材搬送方法及び転写装置
US6516179B1 (en) 1999-10-29 2003-02-04 Ricoh Company, Ltd. Image forming apparatus, image transferring device and recording medium conveying method
JP2001356619A (ja) 2000-06-15 2001-12-26 Matsushita Electric Ind Co Ltd 転写装置
JP2002040818A (ja) 2000-07-26 2002-02-06 Ricoh Co Ltd 画像形成装置
JP2002214943A (ja) 2001-01-23 2002-07-31 Ricoh Co Ltd 画像形成装置
JP2003307944A (ja) 2002-04-18 2003-10-31 Canon Inc 画像形成装置
US20050260015A1 (en) * 2004-05-18 2005-11-24 Kyocera Mita Corporation Image forming device
CN1700119A (zh) 2004-05-18 2005-11-23 京瓷美达株式会社 图像形成装置
JP2006011044A (ja) 2004-06-25 2006-01-12 Fuji Xerox Co Ltd 画像形成装置
JP2006248663A (ja) 2005-03-09 2006-09-21 Canon Inc シート搬送装置及び画像形成装置
JP2006301509A (ja) 2005-04-25 2006-11-02 Konica Minolta Business Technologies Inc 画像形成装置
US20070008397A1 (en) * 2005-07-08 2007-01-11 Canon Kabushiki Kaisha Image Forming Apparatus
US20070110458A1 (en) 2005-11-15 2007-05-17 Tomofumi Inoue Dust container and image forming apparatus
US20070183816A1 (en) 2006-01-30 2007-08-09 Kohji Hatayama Transfer device and image forming apparatus including the same
US20070269233A1 (en) 2006-05-19 2007-11-22 Takeshi Sakashita Image forming apparatus
US20080028967A1 (en) 2006-06-12 2008-02-07 Takeshi Sakashita Image forming apparatus
JP2008003447A (ja) 2006-06-26 2008-01-10 Konica Minolta Business Technologies Inc 画像形成装置
US20080003022A1 (en) 2006-06-28 2008-01-03 Takeshi Sakashita Transfer device and image forming apparatus
JP2008026533A (ja) 2006-07-20 2008-02-07 Kyocera Mita Corp 画像形成装置
US20080050158A1 (en) 2006-08-23 2008-02-28 Kohji Hatayama Power guiding device and image forming apparatus having power guiding device
US20080138133A1 (en) 2006-12-08 2008-06-12 Ricoh Company, Limited Transfer device, image forming apparatus, and waste toner container
US20080193167A1 (en) 2007-01-16 2008-08-14 Ricoh Company, Limited Powder container and image forming apparatus
US20080187365A1 (en) 2007-02-05 2008-08-07 Ricoh Company, Limited Image forming apparatus and powder housing unit
US20080193173A1 (en) 2007-02-09 2008-08-14 Ricoh Company, Limited Belt unit, transfer belt unit, and image forming apparatus
US20080226358A1 (en) 2007-03-13 2008-09-18 Ricoh Company, Limited Image forming apparatus
US20080310893A1 (en) 2007-06-18 2008-12-18 Tomoya Adachi Transfer device and image forming apparatus
US20080316559A1 (en) 2007-06-19 2008-12-25 Konica Minolta Business Technologies, Inc. Laser scanning device and image forming apparatus
US20080317521A1 (en) 2007-06-22 2008-12-25 Tomofumi Inoue Transfer belt device, method of assembling the same, and image forming apparatus
US20080317532A1 (en) * 2007-06-25 2008-12-25 Ricoh Company, Ltd. Image forming apparatus
CN101334620A (zh) 2007-06-25 2008-12-31 株式会社理光 图像形成装置
US20090011882A1 (en) 2007-07-03 2009-01-08 Mitsutoshi Kichise Belt unit and image forming apparatus
US20090016772A1 (en) 2007-07-13 2009-01-15 Tomoya Adachi Belt device and image forming apparatus
US20090014288A1 (en) 2007-07-13 2009-01-15 Takafumi Miyazaki Belt device and image forming apparatus
US20090123201A1 (en) 2007-11-13 2009-05-14 Masanao Ehara Image forming apparatus
US20090129831A1 (en) 2007-11-21 2009-05-21 Takeshi Sakashita Transfer device and image forming apparatus
US20090162114A1 (en) * 2007-12-17 2009-06-25 Makoto Nakura Contacting and separating mechanism and image forming apparatus
US20090285594A1 (en) 2007-12-27 2009-11-19 Mitsutoshi Kichise Image forming apparatus
US20100239334A1 (en) 2008-02-18 2010-09-23 Ricoh Company, Ltd. Image forming apparatus
US20110110685A1 (en) 2009-11-10 2011-05-12 Fuji Xerox Co., Ltd. Image forming apparatus and apparatus exterior unit
JP2011102860A (ja) 2009-11-10 2011-05-26 Fuji Xerox Co Ltd 画像形成装置および装置外装ユニット
US20120057908A1 (en) 2010-09-07 2012-03-08 Ricoh Company, Ltd. Belt unit, transfer unit including the belt unit, and image forming apparatus including the transfer unit
US20120114373A1 (en) 2010-11-08 2012-05-10 Ricoh Company, Ltd. Image forming apparatus capable of effectively utilizing interior space
US20130216260A1 (en) * 2012-02-21 2013-08-22 Seiichi Kogure Image forming apparatus

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
U.S. Appl. No. 13/421,532, filed Mar. 15, 2012, unpublished.

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